The present disclosure relates generally to ophthalmic surgical probes. More particularly, but not by way of limitation, the present disclosure pertains to an enhanced flow vitrectomy probe.
Many microsurgical procedures require precision cutting and/or removal of various body tissues. For example, certain ophthalmic surgical procedures require the cutting and/or removal of the vitreous humor, a transparent jelly-like material that fills the posterior segment of the eye. The vitreous humor, or vitreous, is composed of numerous microscopic fibrils that are often attached to the retina. Therefore, cutting and removal of the vitreous must be done with great care to avoid traction on the retina, the separation of the retina from the choroid, a retinal tear, or, in the worst case, cutting and removal of the retina itself. In particular, delicate operations such as mobile tissue management (e.g., cutting and removal of vitreous near a detached portion of the retina or a retinal tear), vitreous base dissection, and cutting and removal of membranes are particularly difficult.
The use of microsurgical cutting probes in posterior segment ophthalmic surgery is well known. Such vitrectomy probes are typically inserted via an incision in the sclera near the pars plana. The surgeon may also insert other microsurgical instruments such as a fiber optic illuminator, an infusion cannula, or an aspiration probe during the posterior segment surgery. The surgeon performs the procedure while viewing the eye under a microscope.
Standard commercially available vitrectomy probe shafts are of one gauge size (i.e., one constant diameter) from the proximal end to the distal end. U.S. Pat. No. 5,019,035 to Missirlian et al., U.S. Pat. No. 5,176,628 to Charles et al., and U.S. Patent Application No. US 2010/0312169 disclose various types of vitrectomy probes, and all of these patents are incorporated herein by reference. Current trends in posterior segment ophthalmic surgery are driving the development of ever smaller single shafted instrumentation to minimize trauma to the eye. However, as the probes become smaller and less invasive, the working diameter of the probes decreases, which negatively affects the ability of the probe to remove ocular tissue and/or fluid from the eye. As instrument gauge increases (i.e., the diameter decreases), the internal resistance to flow increases, thereby decreasing the rate of removal of ocular tissue and/or fluid from the eye. Moreover, as instrument gauge increases, the stiffness of the instrument decreases, thereby limiting the precise use of the instrument. Consequently, the adoption of smaller diameter instruments has been limited by, among other things, inadequate flow rates due to increased flow resistance and inadequate instrument stiffness.
Therefore, a need exists for an enhanced vitrectomy probe that allows adequate stiffness, reduced flow resistance, and an increased flow rate while maintaining a less invasive, smaller diameter shaft.